Where's the Kepler telescope

Space telescope Kepler has retired

The space telescope, named after the German astronomer Johannes Kepler, has tracked distant planets for more than nine years: the counter on NASA's Kepler website shows more than 5,000 planet candidates. After careful analysis, 2,662 of these have so far been classified as real planets.

The balance sheet of the Kepler space telescope

Kepler's last big discovery before retirement: The hot guy Kepler-90i. Temperatures of more than 420 degrees Celsius prevail on its surface. More than 2,500 light years from Earth, the planet, along with seven others, orbits the star Kepler-90. In December 2017, another solar system was discovered in which eight planets orbit a sun.

Kepler's successors: TESS and Plato

The Kepler space telescope discovered more than 2,500 planets.

A successor to Kepler went into service in April 2018: the NASA TESS (Transiting Exoplanet Survey Satellite) space telescope. The bar is high: the scientists are also expecting more than 2,000 new planetary candidates from TESS.

With a new space probe called "Plato", the European space agency ESA wants to search for "twins of the earth" in the depths of space. The probe is expected to launch from the Kourou space airport in 2026. Plato is said to use 34 telescopes and cameras to look for planets at around a million stars. Among other things, the data should enable conclusions to be drawn about the mass, radius and composition of planets.

How Kepler searched for the "second earth"

When a planet passes in front of its central star, it causes minimal light fluctuations. Kepler registered this and was able to track down exoplanets. Many of the planets and candidates he discovered are gas giants or very close to their sun. Life as we know it is not possible on them. But some of the exoplanets are about the size of the earth and some of them even orbit in the zone around their sun in which earthly life could arise.

Kepler observed a comparatively small area of ​​the Milky Way, but very precisely.

In contrast to other telescopes, Kepler concentrated on a small section of the Milky Way: It observed a field between the constellations Swan and Lyra. The telescope only examined a four-hundredth of the starry sky, but it did so precisely. The telescope kept a close eye on 530,506 stars with its 95 mega-pixel camera during its main mission.

Kepler shows stamina

In mid-August 2013, NASA announced the end of the 600 million dollar mission. The reason: Problems with the control of Kepler. At the end of 2013, however, scientists and engineers announced that they had developed a way to continue using Kepler: The pressure of the photons of sunlight should serve as a replacement for two failed inertia wheels and stabilize the space telescope. This mission began in May 2014 under the name K2. The discovery of new exoplanets showed that the approach was successful.